Recurrent 3 He-rich Solar Energetic Particles

Transcription

1 MPS Solar Group Seminar, 2013 December 10 Recurrent 3 He-rich Solar Energetic Particles Radoslav Bučík see paper Bučík, Innes, Mall, Korth, Mason, Gómez-Herrero 2013, ApJ, submitted Bučík, Innes, Mall, Korth, Mason 2013, in Proc. 33 rd ICRC, paper 0552

2 Outline brief introduction to SEPs properties of 3 He-rich SEPs and motivation approach to the problem (multi-point & multi-instrument); introduce the period of interest observations of 3 He-rich SEPs by different s/c solar sources of 3 He emission summary & further study 2

3 Large (Gradual) SEP events during STEREO era Large SEPs 3 He rich SEPs Reames (1999) 3

4 3 He-rich SEPs : key features One of the most extreme fractionation processes known to occur in astrophysical sites (Mason et al. 1986). anomalous abundances arise from resonant waveparticle interaction (e.g. enhanced f. <10 4! Temerin & Roth 1992; Miller 1998) 2-10 MeV/n 3 He-rich events \ corona enhanced f. 10 enhanced f. 2 3 unenhanced (3 MK) Reames & Ng (2004) larger ionization states of heavy ions than in the corona (Klecker et al. 1984) kilovolt electrons (Reames et al. 1985) & type III radio bursts (Lin 1974; Reames & Stone 1986); minor X-ray flares (Reames et al. 1988) EUV jets near coronal holes (Nitta et al. 2006, 2008; 4 Wang et al., 2006)

5 3 He-rich SEPs : multiple events 195 Å C2 jet times Wang et al. (2006) Wang et al. (2006) multiple events from the same AR with a single s/c (Reames & Stone 1986; Mason et al. 1999, 2000; Wang et al ) recurrent events suggest almost continuous acceleration of 3 He (Pick et 5 al. 2006)

6 Multi-point study of recurrent events 7.1 days co-rotation (ACE) 7.5 days co-rotation Delay between events on different s/c corresponds to co-rotation time similar CL common solar origin? quite high typical of 3 He SEPs 6

7 STEREO-B 3 He-rich event (2011 July 1) AR1244 (NOAA SWPC) July 1 & CIR (all 4 He) events 3 He 4 He +_ Mass histogram reveals clear 3 He peak. 3 He-rich SEPs preceded by an electron event associated with B-class X-ray flare 7

8 STEREO-B 3 He-rich event: Solar Source Identify connection region on Sun Parker spiral for IP space - determines s/c foot-point longitude on SS PFSS model for corona based on SDO magnetograms (Schrijver & DeRosa 2003) check with in-situ magnetic polarity s/c 1AU flare * examine SDO & STEREO EUVI Schatten et al. (1969) 8

9 STEREO-B 3 He-rich event: Solar Source Sine of Heliolatitude Taking into account in-situ polarity STEREO-B could be connected to the both ARs 1243 & Carrington Longitude (deg) marked brightening in AR 1244 but no significant activity in AR 1243 B4.1 4-min difference image around X-ray flare AR the most probable candidate for the 3 He event. 9

10 ACE 3 He-rich events (2011 July 7 & July 9) 275 kev/n Jul 7 Jul 9 Vel. disper Electrons X-ray flare CIR IMF polar - + CIR CIR Pizzo (1978) Polarity 10

11 ACE July 7 3 He-rich event: Solar Source Sine of Heliolatitude 1244 B7.6 Carrington Longitude (deg) ACE connected to same AR as STEREO-B B6.4 4-min diff. images around X-ray flares AR checked with STEREO-A EUVI the same AR was producing energetic electrons & 3 He after almost 7 days this is 1st ever example of such long lasting energetic particle production in solar flare 11

12 ACE July 9 3 He-rich event: Solar Source Sine of Heliolatitude 1246 Carrington Longitude (deg) In-situ polarity: ACE connected to low-latitude CH Time of particle release on the Sun unknown no X-ray flare & solar electrons, 3 He onset dispersionless the emergence of AR 1246

13 ACE July 9 3 He-rich event: Solar Source Reames (2002) coronal hole jet 1246 jet time type III burst at the time of the jet escaping electrons reached 1 AU ACE not connected to AR He onset - 8 hours after jet (consistent with travel time to 1 AU) 13

14 STEREO-A 3 He-rich event (2011 July 16) no solar electron event before 3 He increase anti-sunward sunward the onset dispersionless only slight anisotropy; reflecting boundary beyond the observer ion intensities start at the stream interface with a maximum in the vicinity of CIR trailing edge such features typically observed in CIR events consistent with simulations of 3 He-rich SEPs in CIRs (Kocharov et al. 2003, 2008) 14

15 STEREO-A 3 He-rich event: association with CIR CIR model Simulated 3 He SEPs at 1 AU CIR with CIR with no CIR Kocharov et al. (2008) Kocharov et al. (2008) 3 He-rich SEPs could be trapped and re-accelerated in CIRs 15

16 STEREO-A 3 He-rich event: Solar Source Sine of Heliolatitude 1246 Carrington Longitude (deg) STEREO-A connected to same CH as ACE during July 9 event

17 STEREO-A 3 He-rich event: Solar Source the brightenings coincide with type III escaping electrons reached 1 AU STEREO-A not on field lines connected to AR 1246 candidates for populating the CIR 17

18 Summary the study for the 1 st time presents observations of: 1. solar regions with long-lasting conditions for 3 He acceleration 2. solar energetic 3 He that is temporary confined/reaccelerated in interplanetary space the two examples show that solar regions with different size/morphology/flaring could produce a 3 Herich event with new high cadence images on multiple s/c the properties of 3 He solar sources could be probed as never before 18

19 Next study: other recurring 3 He-rich SEPs? We have identified another 11 cases when 3 He-rich SEPs from the same AR were consecutively seen on ACE and STEREO-A events Properties of associated jets investigated by Martina Chen (new postdoc at MPS). 19

20 Next study: what type of flaring? Long-lasting 3 He source: ACE Feb 8, STEREO-A Feb UT 95 Å 195 Å 195 Å loops? jet? twisted eruption? where is the source of 3 He in large ARs? is always newly emerging (small) region required for 3 He production? 20

21 Thank you! 21